Any place on a picture where you find an extremely distracting rack that makes the rest of the picture irrelevant. It is so distracting that the viewer doesn’t even notice that there is a foreground and / or background… because there isn’t, there is only a rack. Objects in the rackground may appear closer than they actually are.

It is similar to a photobomb as the rack totally hijacks the original focus of the picture. As such, the rack(s) in the rackground are also known as photobombs.

Q: Did you see the cows in the background?
A: There were cows in that picture? Sorry, I couldn’t see anything other than that chick in the rackground.

I was so happy to see that my picture got unintentionally photobombed by that hot school teacher in the rackground.

Did you see the photobombs on that girl in the rackground? I would've totally asked her out if he had seen her earlier.